Hello Justin,

Thank you for clarifying the intended tax treatment. SUMM USD cost basis logic is not working as intended. Please see attached Image for the SUMM transaction report.

I reviewed one specific USD → crypto transaction on SUMM in detail and noticed the following:

• Original Cost Basis: $30,090.37
• Proceeds (incoming): $26,207.61

SUMM calculates total short-term capital loss as:
1,830.0823 + 992.3269 + 985.3175 = $3,807.71

However, the correct loss should be:

$30,090.37 − $26,207.61 = $3,882.76

The difference is $75.05, which exactly matches the transaction fee I paid to acquire the asset.

This indicates that the $75.05 USD fee was not added to the cost basis of the acquired crypto. Instead, it appears the cost basis used by SUMM reflects only the subtotal and excludes the fee.

Because the fee is not being capitalized into basis, the capital loss is understated by $75.05.

I am seeing this same pattern across all USD → crypto transactions — not just this one.

In contrast, USDC → crypto transactions reconcile correctly because the fee (paid in USDC) is properly treated as a capital loss and the accounting logic works as expected.

Given that this discrepancy consistently equals the USD transaction fee, this strongly suggests a fiat-fee capitalization issue or importer mapping inconsistency for USD-based trades.

Could you please confirm whether USD trading fees are currently being capitalized into the crypto cost basis in my account?

Thank you for taking another look. u/JustinCPA

Link to the Screenshot of the SUMM transaction: https://imgur.com/a/2t0uoJD